SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8008600c7e7012c06db967648a5f99320fda9b3f50c53b931dfbeef7ea927b3e' 
  AND token = 'Mtit/l9TuQPrsqjcRLyRHS6grIdlqXbfPKmSLwf6teU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}